Question

Is there a better way to write this:

if myarray.include? 'val1' ||
   myarray.include? 'val2' ||
   myarray.include? 'val3' ||
   myarray.include? 'val4'

Answer 1

Using set intersections (Array#:&):

(myarray & ["val1", "val2", "val3", "val4"]).present?

You can also loop (any? will stop at the first occurrence):

myarray.any? { |x| ["val1", "val2", "val3", "val4"].include?(x) }

That’s ok for small arrays, in the general case you better have O(1) predicates:

values = ["val1", "val2", "val3", "val4"].to_set
myarray.any? { |x| values.include?(x) }

With Ruby >= 2.1, use Set#intersect:

myarray.to_set.intersect?(values.to_set)